<template>
  <label :class="['hm-checkbox', { 'is-checked': isChecked }]">
    <span class="hm-checkbox__input">
      <span class="hm-checkbox__inner"></span>
      <input type="checkbox" class="hm-checkbox__original" :value="label" :name="name" v-model="model" />
    </span>
    <span class="hm-checkbox__label">
      <slot></slot>
      <template v-if="!$slots.default">{{ label }}</template>
    </span>
  </label>
</template>

<script>
export default {
  name: 'HmCheckbox',
  inject: {
    CheckboxGroup: {
      default: ''
    }
  },
  props: {
    value: {
      type: Boolean,
      default: false
    },
    name: {
      type: String,
      default: ''
    },
    label: {
      type: String,
      default: ''
    }
  },
  computed: {
    model: {
      get () {
        return this.isGroup ? this.CheckboxGroup.value : this.value
      },
      set (newVal) {
        // 派发给父组件 input 事件
        this.isGroup ? this.CheckboxGroup.$emit('input', newVal) : this.$emit('input', newVal)
      }
    },
    isGroup () {
      return !!this.CheckboxGroup
    },
    isChecked () {
      // 如果 group 包裹 判断 label 是否在 model 中
      // 如果没有 group 包裹，直接使用 model
      return this.isGroup ? this.model.includes(this.label) : this.model
    }
  }
}
</script>

<style lang="scss">
  .hm-checkbox {
    color: #606266;
    font-weight: 500;
    font-size: 14px;
    position: relative;
    cursor: pointer;
    display: inline-block;
    white-space: nowrap;
    user-select: none;
    margin-right: 30px;

    .hm-checkbox__input {
      white-space: nowrap;
      cursor: pointer;
      outline: none;
      display: inline-block;
      line-height: 1;
      position: relative;
      vertical-align: middle;

      .hm-checkbox__inner {
        display: inline-block;
        position: relative;
        border: 1px solid #dcdfe6;
        border-radius: 2px;
        box-sizing: border-box;
        width: 14px;
        height: 14px;
        background-color: #fff;
        z-index: 1;
        transition: border-color 0.25s cubic-bezier(0.71, -0.46, 0.29, 1.46), background-color 0.25s cubic-bezier(0.71, -0.46, 0.29, 1.46);

        &:after {
          box-sizing: content-box;
          content: '';
          border: 1px solid #fff;
          border-left: 0;
          border-top: 0;
          height: 7px;
          left: 4px;
          position: absolute;
          top: 1px;
          transform: rotate(45deg) scaleY(0);
          width: 3px;
          transition: transform 0.15s ease-in 0.05s;
          transform-origin: center;
        }
      }

      .hm-checkbox__original {
        opacity: 0;
        outline: none;
        position: absolute;
        margin: 0;
        width: 0;
        height: 0;
        z-index: -1;
      }
    }

    .hm-checkbox__label {
      display: inline-block;
      padding-left: 10px;
      line-height: 19px;
      font-size: 14px;
    }
  }

  // 选中的样式
  .hm-checkbox.is-checked {
    .hm-checkbox__input {
      .hm-checkbox__inner {
        background-color: #409eff;
        border-color: #409eff;

        &:after {
          transform: rotate(45deg) scaleY(1);
        }
      }
    }

    .hm-checkbox__label {
      color: #409eff;
    }
  }
</style>
